The invention relates to airborne-sound-absorbing wall or ceiling paneling consisting of a perforated plate having a hole-area proportion L and, bonded thereto by means of a discontinuously distributed adhesive layer, a nonwoven fabric having an open-area proportion N and an air flow resistance W.sub.v in the zones free of adhesive, said perforated plate being mounted at a spacing from the wall or ceiling that is large in relation to the thickness of the nonwoven fabric, and said paneling having a total air flow resistance W.
The physical bases for the design of paneling of this type are dealt with in detail in "Wirtschaftliche Gestaltung von Schallschluckdecken" (Economic design of sound-absorbing ceilings), by G. Kurtze, which appeared in VDI-Z 119 (1977), No. 24, p. 1193 et seq. According to that paper, the use of a thin nonwoven will result in broad-band, effective sound attenuation if it can be rigidly disposed at a spacing from the wall of the room to be soundproofed that is large in relation to the thickness of the nonwoven. The effect so utilized is illustrated by an example which relates to a metal coffer 70 mm deep which on its face is covered by a perforated metal plate having a thin nonwoven fabric bonded directly to its underside. In bonding the two parts together, care must be taken to assure that the air flow resistance of the nonwoven layer is not increased in an undefined manner. For this reason, the adhesive must not be applied to the nonwoven fabric, which complicates the bonding operation. Another drawback is that relatively narrow limits are imposed on the perforations of the metal plate with respect to type and to proportion of the hole area, and these often make it impossible to design the side exposed to view as desired.